Electric plug



- W. H. CLARK ELECTRIC PLUG May 10, 1927. 1,627,594

Filed April 3. 1922 Patented ll), i927.

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ELECT ERIC PLUG.

Application filed April '3, 1922. Serial No. 549,218.

5 sity of screwing it in the socket to interengage the threads in the usual manner, and which will be firmly held in proper position in the socket to provide the desired electric connection.

A further object of the invention is to provide a threaded resilient electric plug which can be screwed into a threaded electric socket in the usual manner or which can be pushed into the socket or pulled out of the socket without screwing or unscrewing to make a quick connection or disconn'ection.

In the accompanying drawings I have shown selected embodiments of the invention and referring thereto Fig. 1 illustrates my invention applied to an ordinary electric socket which is shown partly in section;

Fig. 2 is a sectional view of the plug on the line 22 of Fig. i;

Fig. 3 is an elevation of the plug, partly in section; v

4 is a sectional view of the plug on the line st l of Fig. 2;

5 is a sectional 'view of a modified form of the plug illustrated in the preceding figures; and

6 is a top plan view of the resilient shell showing the contact lip before it is bent to the position shown in Fig. 5'.

Referring to the drawings, 7 illustrates one type of an electric socket which is pro vided with a threaded holder 8 of the usual form adapted to receive an electric bulb or plug as desired. My invention is adapted for use with different forms of electric sockets and it will be understood that the one herein shown is simply selected for the purpose of illustration.

The plug body 9 is made of insulating material and is providedwith a peripheral groove 10 surrounded by a guard flange 11. A one-piece metal shell 12 is secured on the plug with its free end arranged in the groove 10. This plug is screw-threaded to interengage with the thread of the holder and it may be screwed into the holder in the usual manner but in order that it may be more quickly inserted and removed I split the plug at 13 to divide it into a corresponding number of sections 14 which are sufficiently resilient to enable the plug to he pushed without turning into proper position in the holder or to be withdrawn therefrom without turning. The groove is of suiiicient width to permit the required movement of the shell sections when inserting or removing.

the plug from the holder. The shell is sl ghtly conical in shape or the free ends of its sections may be otherwise shaped to spread outward slightly so that under nor mal conditions when the plug is not inserted in the socketthe outer ends of the sections will he against or closely adjacent to the outer wall of the groove, as shown in'Figs.

2 and 5. lVhen the plug is inserted in the socketthe sections will compress to accommodate the shell to the holder and the resiliency of the metal sections under this compression is sufficient to hold the plug securely within the socket t0 ll01 1n the required electrical connection. When the plug is withdrawn from the socket the resilient. sections will yield sufiiciently to enable the shell to be readily disengaged from the holder by an outward pull. The side wall 9 of the plug body 9 may be straight or it may be curvedor dished, as shown inFigs 2 and 5 to accommodate the shell sections under the compression action resulting when the plug is'inserted in and removed from the socket. I V j The shell be secured to the plug body in any suitable manner as by an insulating disk which engages the top of the shell and is fastened to the plug body a screw 16. v passes through a bore 18 in the plug body and the disk and is secured to the screw 16 which forms one of the plug terminals.

The top of the shell is provided with a central opening 19 and an annular flange 20 to which the shell sections 14 are integrally connected. I prefer to cut notches at each side of each slit 13 in the bend forming the juncture between the sections and the flange (Figs. 4%, 6) to provide greater resiliency and freedom of movement for the sections. In the construction of Fig. 4 the flange 20 is cut away at 22 leaving an open space and a bridge is seated in a recess 2% in the plug body and is bent upward and outward over the upper corners of said recess and has its ends located beneath the flange 20 of the shell adjacent the cut away portion 22 2-4). The other circuit wire 17 passes through a bore 18' in the One of the circuit wires 17 plug and is fastened to the bridge 23 and the plug by a screw 25. Thus the circuit wire 17 is connected through the screw 25 and the bridge 23 with the shell 12 which forms the other terminal. The disk 15 may be provided with a lug 15 to engage the recess in the bridge where it fits into the recess in the plug body so that opening :26 for the screw 16 and opening 27 for the circuit wire 17 in the dislt may be easily registered in assembling with the corresponding openings in the plug body.

I contemplate stamping the shell out of sheet metal and since it is desirable in constructing devices of this character to reduce the number of parts to a minimum I may make the shell, as shown in Figs. 5 and 6, with a lip 28 projecting from the flange 20 into the opening 19 and adapted to be turned down to engage the recess 24 in the plug body. In this case the screw 29 for securing the circuit wire 17 is inserted transversely in the plug body. as shown in Fig. 5, instead of longitudinall of the plug body, as shown in Fig. 2'. This construction dispenses with the separate bridge member of Figs. Qr-i: and for that reason is a preferable construction.

My invention provides a simple and inexpensive electric plug which can be easily and quickly inserted in and removed from electric sockets adapted to receive such plugs or light bulbs, and it can be inserted and removed with a screwing movement as commonly employed or by a simple iii-thrust or out-pull when a quick connection or disconnection is desired. My improved plug can be made at low cost to sell in competition with present plugs and while I have disclosed what I now believe to be desirable embodiments of the invention 1 do not wish to be understood as restricting myself to these particular constructions but I reserve the right to make all changes in the form,

construction, arrangement and proportion of parts as fairly fall within the scope of the following claims:

I claim:

1. As an improved article of manufacture, an electric plug comprising a body of insulating material having a peripheral groove and guard flange, a one-piece metallic shell with plurality of resilient sections extending lengthwise of tne body and spaced therefrom with their ends freely. movably received within said groove with limited freedom of movement toward and from said flange, the other end of the shell having a central opening and an annular flange in-- tegral with said sections, said flange resting upon the end of the plug body with interengaging recess and portion of the shell adjacent said flange, and a disc over the top of said shell and "fastened to the plug, said plug body having bores for the circuit wires extended theretlu'ough, and means securing said disc to the body and serving for securing said disc in place and an attachment for one of said wires.

2. ills an improved article of manufacture, an electric plug comprising a body of insulating material having a peripheral groove and guard flange, a onepiece metallic shell with. a plurality of resilient sections extendin g lengthwise of the body and spaced therefrom with their ends freely movably received Within said groove with limited tree- (lOlll of movement toward and from said flange, the other end oi the shell having a central opening and an annular flange integral with said sections, the said flange being cutaway leaving an open space, the plug l)OC y having a recess, a bridge seated in said recess and bent upward and outward over the upper corners thereof with its ends located beneath the flange ot the shell adjacent said cutaway portion, and a disc having a lug engageable in the recess in the bridge and fitting into a recess in the plug body, said recess being adapted to receive securing means cngageable withsaid flange, as and for the purpose specified lVENDELL' H. CLARK. 

